PWM-CSI induction motor drives with phase angle control

A pulse-width-modulated current source inverter (PWM-CSI) drive system using an induction motor is described. Its dominant feature is that it provides adequate control of either torque or speed over a wide range without requiring a shaft position or speed sensor. The drive is simple to implement, rugged and sufficient for many controlled drive applications. The control strategy is based on the concept of controlling the stator phase angle of the induction motor. The stator voltage is sensed and the current source inverter is used to inject current into the motor with the desired phase angle. The system incorporates modulation techniques for harmonic control described in a comparison paper (see Conf. Record 1989 IEEE IAS Annual Meeting, pt.I, p.508-513, 1989).<>